Electric heater for oil-wells.



N0. 806,039. PATENTED NOV.28, 1905. J. E. WILLIAMSON & C. E. COLLINS.

ELECTRIC HEATER FOR OIL WELLS.

APPLICATION FILED JAN. 23, 1896.

'attouwq witmmmlo 5% K UNITED STATES PATENT OFFICE.

JAMES E. W ILLIAMSON AND CHARLES E. COLLINS, OF ALLEGHENY, PENNSYLVANIA. ASSIGNORS, BY MESNE ASSIGNMENTS, OF ONE- THIRD TO AMALIA S. OONNELLY, OF PITTSBURG, PENNSYLVANIA.

ELECTRIC HEATER FOR OIL-WELLS.

Specification of Letters lfatent.

Patented Nov. 28. I906.

Application filed January as, race. spin at. 676,661.

and exact description of the invention, such as;

will enable-others skilled in the art to which it pertains to'make and use the same, refernce being had :to the accompanying drawings, '5.

which form a' part of this specification.

-- -Figure l 'isj'a partial side elevation of our improved heater. Fig. 2 is a verticalsection. Fig. 3 is a transverse section on the line a: w of Fig. 2. v.

It has been heretofore proposed to heat the lower parts of oil-wells by means of a section of electric,circuit of relatively high resistance to be placed at or near the bottom of the well; but serious difiiculties have been experienced in using any of the devices for this purpose with W hi ch we are acquanted. The earlier plans for this purpose have required the renaegal of the-pump-tubing from the well to permit of the entrance of the heating devices or have secured the heater rigidly to the lower part of the pumping-tube. The first-mentioned of these earlier plans is objectionable, because as soon as the heater is withdrawn the previously-liquefied parafiin and viscid materials tend to harden, so that by the time the pumping apparatus is again introduced into the well all the beneficial results incident to the use of the heater have been lost; and when the second of said earlier plans is followed the heater, being permanently fixed at the lower end of the pumping-tube, is adapted to operate only at the bottom of the well, and it is impossible to withdraw the heater for any purpose or vary its vertical location in the well without removing or lifting the entire pumping-tube.

The object of the present invention is to provide an electric'heater which can be readily introduced at any time to the bottom or any desired portion of a well and as readily withdrawn therefrom without requiring the withdrawingof any of the pumping apparatus.

In the drawings, 1 indicates a tube or cylinder adapted to constitute the external casing of the body part of the heater. It is screw-.

threaded at the ends and b'y'thethreads is connected with a plug 3 at the bottom and a .plug 3 at the top. These plugs are provided with central apertures, and in these apertures a central tube 4 is tightly fitted in such way' as to make a water-tight joint at each end. These parts 1 3 3 4 when secured together inclose a water-tight chamber, within which the parts of the heater proper are arranged.

The inner tube or cylinder 4,which is of such diameter as to fit loosely about and adapted to inove longitudinally of the pump-tube 5, is

electrically insulated on its outersurface in any suitable way and has coiled around it or otherwise applied to it a resistance-coil 6, for

which ,at present we prefer to use Germansilver wire. The terminals of this resistancecoil are carried through the upper plug 3. For this purpose the latter has two apertures, in which are tightly fitted porcelain or equivalent tubes 9 10. The tube 10 passes through the upper plug 3 and downward into the chamber formed by the tube 1 and the plugs 3 3 in order to insure the complete insulation of the long terminal wire leading from the lower end of the resistance-coil through said tube.

The tubes 9 10 are extended upward asuitable distance above the upper plug 3 in order to give a prolonged support for the wires they tubes 9 1O ..nd,may have stufling-boxes or packings to fit the upper ends of said tubes.

2 2 are hooks or equivalent devices project ing from said supplemental cylinder or was ing for attaching the carriers, cords, wires, or the like by which the implement is supported and by which it is lowered and raised in the well.

The method of operation of these devices will be readily understood. The heat generated by the current when passing through the resistance-coil 6 is radiated from the chamber within which said resistance-coil is mounted and through the tube 1 to the surrounding jrzsted upon the pump-tube 5 to permit of 1 being removed from or inserted into the well without varying the position of said pumptube, and the heater can be held at any desired point in the length of the tube 5. It

- will also be noticed that the terminals'of the resistance-coil are protected by the tubes 9 10 and the supplemental casing surrounding the upper portions of said tubes fora considerable distance. This latter construction prevents the conductors from bending at points adjacent to the coil 6, and they are also thereby held away from and out of contact with the walls of the well, whereby any danger of rubbing off the insulation during the adjustments of the heater is prevented.

W a e claim is 1. In an electric heater for oilwells, the combination, with the oil-pumping tube, ofa heater separate and separately removable therefroinfiand'having a. casing and an inner aoe'pso tube surrounding said pumping-tube, means connecting said casing and inner tube and forming a closed annular chamber, an electric resistance in said chamber, having suitable terminals leading out of the same and means for raising and lowering the heater around the pumping-tube, whereby different sections of said tube may be heated.

2. In an electric heater for oil-wells, the

combination with the pump-tube of an electric resistance in an electric circuit arranged to surround said 1 tube and adapted to be adjusted longitudinally thereof to heat said tube ifit wfiatever point desired, substantially as set or't 3. In an electric heater for oil-wells, the combination with the tube or pipe adapted to conduct the oil from the well, of an electric resistance adapted to be adjusted longitudinally of said tube to heat the tube at whatever point desired.

In testimonythat we claim the foregoing we hereunto afiix our signatures this 20th day of June, A. D. 1895.

JAMES E. witmasoa." [n.aj CHARLES a'cattms. [L.s.] In presence of- JAB. J. MOAFEE, C. O. WILLIAMS.' 

